Published online by Cambridge University Press: 31 May 2012
During their reproductive period, white pine weevils, Pissodes strobi Peck., remain on susceptible Sitka spruce trees, Picea sitchensis (Bong) Carr., that are suitable for their reproduction and progeny development. Weevils depart from resistant Sitka spruce trees, where weevil reproduction is inhibited or blocked by resistance (Sahota et al. 1994). This resistance appears to work by interfering with the juvenile hormone (JH) system of the weevil (Sahota et al. 1994; Leal et al. 1997). In our experiments to investigate whether or not interference with JH could also account for the weevils' domicile at susceptible trees and their departure from resistant trees (see Sahota et al. 1994), we routinely treat weevils with hormones and study their flight behaviour in the laboratory and field.